Drill pipe protector



April 16, 1940.

w. G. L. SMI TH DRILL PIPE PROTECTOR Filed Jan. 12, 1958 A r TOR/V5145.

?atented Apr. 16, 'IlQdQ pairs tree FFEQE 8 Glaime.

My invention relates to devices for protecting drill pipe, morespecifically protective collars adapted to embrace drill pipe.

In the drilling of a well, a relatively long string of drill piperotating inside a larger casing will inevitably tend to frictionallyengage the outer casing at random points. To prevent excessive resultantwear of the outer casing and of the couplings and tool joints in thedrill string, it is customary to mount resilient collars or protectorsat spaced points on the drill pipe, the protectors being larger indiameter than the couplings or tool joints of the drill string.

The present invention refers to a split pipe protector that may beopened and then releasably closed to avoid the necessity of slipping theprotector over an end of the drill pipe. In a protector of this type, ametal reinforcement means having the character of a core or internalframe is embedded in the resilient body of the pipe protector tocooperate with means for re-- leasably connecting the ends of theprotector together. The embedded reinforcement takes care of variousstresses exerted through the body, including the stresses engendered bythe drawing together of the ends of the protector in mounting the deviceon drill pipe.

One of the dimculties heretofore encountered I in this art is that thebulk required for adequate strength in the internal reinforcement hasbeen so great as to leave insumcient room for adequate thickness of theresilient material forming the enveloping body. One of the objects of myinvention is to provide a combination of internal reinforcement meansadequate for all stresses met in service, but, nevertheless, relativelythin to permit maximum thickness of the surrounding resilient material.My invention in this aspect is characterized'by the combination of aprimary reinforcement in the form of an embedded band to receivelongitudinal stresses through the drill pipe protector, together withsecondary reinforcement means to take care of other stresses. Icontemplate forming relatively large apertures in the band, therebyreducing the bulk of the band and relying upon the secondaryreinforcement means disposed acrosssaid apertures. Certain additionaladvantages that will be apparent in my detailed description result fromthis.

Another problem commonly noted in the art is the tendency of thematerial of the resilient body of the protector to peel away from theinternal reinforcement means, especially when such means comprises aband having extensive smooth like material against a relatively smoothsurface. 1Q

My invention is characterized by the conception that this object may beattained by combining with the smooth primary reinforcement a perforateor cribriform secondary reinforcement Lying adjacent the smooth surfaceof the 15 primary reinforcement and connected thereto at spaced points,so that the resilient material of the protector body may permeate thesecondary reinforcement and have portions locked in a positive mannerbetween the two reinforcements. 20

I have discovered that a bond of even greater efiiciency between thecribriform means and the band may be attained if the band isdiscontinuous or apertured to provide spaces spanned by the cribriformmeans, an especially efi'icient bond as being achieved if two layers ofthe cribriform material are provided to overlie both faces of the metalband. ()ne of the objects of my invention is to apply this latterconstruction to the reinforcement of the resilient body adjacent thepro- 39 trudlng ends of the embedded band to prevent peeling of theresilient material.

The above and other objects of my invention will be apparent from thedetailed description to follow, considered with the accompanying draw-35 ing.

' In the drawing:

Fig. l is a side elevation, partly in section, showing the protectormounted on a section of drill pipe.

Fig. 2 is a side elevation of the internal reinforcement, partly brokenaway, with the resilient body removed.

Fig. 3 is a side elevation of a portion of the internal reinforcingband.

Fig. l is a transverse section taken. as indicated by the line ll ofFig. 1.

Fig. 1 shows my protector, generally designated by the numeral it,mountedon a drill pipe ll, the protector comprising a body 12 that isprei-- 5Q erably'molded from a resilient material, for example, rubberor the like. The body 12 is split to form two opposed ends it and It,and has a "longitudinal channel it to permit a hinge action 7 when thetwo ends are spread apart for mountreinforcementv means I?! having of arelatively rigid split band designed to with- I standlongitudinalstresses and alsoxto serve as v meansfor. placing theprotector under tension icircumferentially. To provide for a hinge atthe 1 ing the protector on drill pipe.v Preferably, the body is. ofstreamlined contounbeing tapered adjacent its upper and lower-led es toprovidev conical surfaces [6. j f Embedded in the resilient body thecharacter channel 15 ofthe body,the band i! may be 7 made in twosectionslla and i-lb having dovetailed tongues 48 looped to embraces. hinge vFor the purpose of securing the other ends of the band sections Na andi'lb togethenthey may i I i be formed with dovetailedtongues 2B, whichare.

, formed into flat loops 2 l vtoreceive a flat tapered width from oneThe fiat loops 2i decrease in end of the pipe protector to the other endin agreement with the taper of the pin loci-ring pin 22.

i i 2i, solthat when the pin is driven into iplace toward theposition'indicated in Fig. Litdraws producing circumferentialconstriction of thememay be substantially reduced in weight by aperi Forexample, each of the two'collar'sections 11a and ill) may Bjlargaapertures-'23. .The edges of, each aperture is 1 be cut away, to providerelatively may bestren'gthened'by forming a; flange 24; the

, flange being turned over to provide anchorage for: the materialofztheresilient body I2. Y

.I. have found that if the'secondary reinforcement to take care ofvarious lateraljstressesiis in 1 the form of a; perforate or :cribriformsheet laid along the band and attached theretoat "spaced in-' I'tervals. such secondary reinforcement will serve l 1 additionally a,mechanical'bonding agent forholding the material of the resilient bodyagainst the band, the secondary reinforcement, in effect, anchoring therubber body to the band. I have found that even if an attempt is made tofit such a secondary reinforcement uniformly snug against the smoothsurfaces of the primary reinforcement, the material of the resilientbody in the molding process will encase the perforate secondaryreinforcement and have portions locked between the two reinforcements.Preferably, woven wire screen will be employed, one advantage being thatwherever the wires cross in the weave, effective spacing for anchorageis insured, another advantage being that a round wire has an anchoragevalue even when it lies fiat against a smooth surface with nointervening space.

In the drawing I show a sheet of woven wire 25 lying against the innerface of each of the band sections i la and I lb, it being understood, ofcourse, that the wire screen may lie against either face of the band. Itwill be noted that the screen spans each of the band apertures 23. Thecross-section represented by Fig. 4 shows that in my construction thecentral portions of the protector have maximum resilient material withminimum embedded metal, and, since the embedded reinforcement is ofreticulate character, the body I2 is not divided into independent innerand outer strata. I

While it is apparent, as previouslyexplained, that a wire screen orother perforate sheet lying against a smooth surface and attachedthereto at space'd points will anchor asu rroundingresilient body to thesmoothsurface, nevsrtholcsl :in such construction only relatively thinlayer: v i of the resilient material are locked between tin i2 is aprimary 1 wire screen and the primary reinforcement. A feature of myinventionis the conception'that the anchorageof the screen orperforatesheetin the'resilient material may be made exceptionallyeffective by cutting, away portions of the primary reinforcement so 7the resilient material may lie on both sidesoi the embeddedscreen orperforate sheet. 1 I I n i A further feature of. my invention is the comthat substantial thicknesses a:

- ception thatby cutting away the primary reinforcement at spaced areas,I may provide a series of successive zones in. which provision is madefor,

attaching the secondary reinforcement to I the prlmaryreinforcement andalternately for anchoringthesecondary reinforcement with max- .imum'effectiveness in "the resilient material;

This construction involving a series of zones is employed preferably toinsure an eifective bond between the: resilient material and the primaryreinforcement where the primary reinforcement pr otrudes fromQthef, bodyof the protectonfor ex- Y ample, vinthe vicinity of the hinge ofthelband near the loops 2| for securing together theopen vi ends of theprotector. The :purposeofproviding the relatively long tongues ll atthevhinge vof the protector; and they relatively long tongues 18 Y:neart e open ends of the protector is to provide in the assembleddevice a series of spaced :open-g j j ings 26, as indicated in vFig.2.

, Inthe preferred form 'of my invention, I pro. i 1

yids two layers of the secondary: reinforcement a extending over such azone, one layer being'on i reinforcement. Thus. j

21 of the woven ,wire' lying over the outsidefaccs of the tongues i eachside of the primary in Figs. 2 and 4, I show: strips,

; ofthe bands oppositecorresponding portions of w flthe innerlreinforcement sheet fl. The sec-f I ,ondary reinforcement material maybe attached I to the bands Ila and 11b in any suitable manner. but, bypreference, I simply spot-weld the screen material to the band atvarious points as indicated at 28, and where the two layers of screenextend beyond the edges of the band I may connect them together byspot-welding, as indicated at 29.

The specific embodiment of my invention chosen for the purpose of thisdisclosure is 11- lustrative only and suggests a wide range of changesand modifications within the spirit of my concept. I reserve the rightto all such changes and modifications that are covered by my appendedclaims- I claim as my invention:

1. A pipe protector of the class described, comprising: a split circularbody of resilient material: a split band embedded in said body. saidband having apertures; means to releasably connect the opposed ends ofthe band; and a perforate metal sheet embedded in said resilient bodyand spanning apertures of said band, said perforate sheet being attachedto said band and being sufficiently coarse in its-perforations toprovide substantial bonding through the sheet of the portions of saidbody that lie on opposite sides of the sheet, whereby the perforatesheet will prevent 7 said resilient material from peeling away from saidembedded band. 2. A pipe protector of the class described, comprising: asplit circular body of resilient material; a split band embedded in saidbody with its ends protruding from the body; means to releasably mconnect said ends of the band; and cribriform material embedded in saidbody and attached to said band, said cribriform material lying on boththe inner side and the outer side of said band, said cribriformreinforcement being of such coarseness in mesh that the portions of saidbody on the opposite sides of the reinforcement are interconnectedtherethrough with substantial bonds whereby said cribriformreinforcement anchors said body against said band.

3. A pipe protector of the class described, comprising: a split circularbody of resilient material; a split band embedded in said body, saidband having spaced tongues extending from the split ends of said body;and cribriform material embedded in said body and attached to said band,said cribriform material lying against both the inner side and the outerside of said band and extending over the spaces between said tongue saidcribriform material being of such coarseness in mesh that the portionsof said body lying on opposite sides of the cribriform material areinterconnected through the material.

4. A pipe protector of the class described, comprising: a split circularbody of molded material, said body being cut away to fbrm a longitudinalchannel for hinge action; a split metal band embedded in said body withits split edges protruding from the ends of the body, said band havingat least one relatively large aperture; means to releasably connectopposed ends of the band at the split thereof; and a metal cribriformreinforcement embedded in said body and spanning said aperture, saidmember being attached to said band, said cribriform reinforcement beingof such coarseness that the portions of said body lying on oppositesides thereof are interconnected therethrough with substantial bondswhereby said cribriform reinforcement holds said body against said band.

5. In a device of the character described, the combination of: a moldedbody; a reinforcement member for said body; and means for anchoring thebody to the reinforcement member, said means comprising a perforatemember embedded in the body and overlying extensive surfaces of thereinforcement member, said perforate member being attached to thereinforcement member at spaced points and out of contact with thereinforcement member between said spaced points, the perforations ofsaid perforate member being dimensioned to provide substantial bondingthrough the tions of said body perforate member of the porthat lie onopposite sides of the perforate member to prevent the material of themolded, body from peeling away from said reinforcement member. V

6. In a device of the character described, the combination of: a moldedbody; a reinforcement member embedded in said body, said reinforcementmember having a series of spaced openings; and means for anchoring-thebody to the reinforcement member, said means comprising a perforatemember embedded in the body and extending over said openings, saidperforate member being attached to said reinforcement mem-- berintermediate said openings, the perforations of said perforate memberbeing dimensioned to provide substantial bonding through the perforatemember of the portions of said body that lie on opposite sides of theperforate member, whereby the perforate member prevents material of saidbody from peeling away from said embedded reinforcement member.

7. In a device of combination of: a molded body of annularconfiguration; a. relatively rigid metal wall member embedded in saidbody for the reinforcement thereof, said wall mmber being cut away toprovide an opening therethrough'; and means to anchor said molded bodyto said'wall member to prevent the molded body from being separatedoutwardly from the wall member, said means comprising a perforate metalsheet embedded in said body on the inner side of said wall member in aposition extending over said opening, the perforations of said sheetbeing dimensioned to provide substantial bonding through the sheet. ofthe portions of said body that lie on opposite sides of the sheet.

8. A pipe protector of the class described, including: a split circularbody of resilient'material; a split band embedded in said body; means toreleasably connect the opposed ends of the band together; and a metalreinforcement embedded in said body the body from peeling away from saidband, said reinforcement having numerous apertures to give it aperforated character, said apertures being large enough that portions ofsaid body on opposite sides of the reinforcement are interconnectedtherethrough with substantial bonds, said reinforcement being attachedto said band at spaced points, said reinforcement being spaced from theband and separated from the band by the material of said bodyintermediate; said points of attachment.

. WALTER G. L. SMITH.

to prevent the material ofthe character described, the I

